It is known to use an air purifying respirator to remove tritiated water vapor from the atmosphere. Presently, the exchange of higher hydrogen isotopes is achieved by using vermiculite beds. More recently respirator filters have been provided for the removal of tritiated water which include a filter material having a high surface area such as silica gel and activated carbon.
The efficacy of these filters is tested by passing tritiated water vapor through the filter until breakthrough is encountered. The gas passing through is measured for the tritiated water present. When the filter is unable to remove 95% of the tritiated water entering the filter, breakthrough is deemed to have occurred. Most specifications require that a 95% removal rate be maintained for at least 60 minutes.
However, because the methods available to test the efficiency and efficacy rely upon the use of tritiated water, manufacturers of respirators are required to send their devices to special laboratories equipped and licensed to handle tritiated water in order to determine whether or not their respirators meet specifications. This is both expensive and inconvenient.
Accordingly, it is an object of the present invention to provide a test method which does not involve the use of tritiated water but provides a reliable correlation with tritiated water tests. It is a further object of the invention to provide a test for testing the efficacy of tritiated water respirator canisters and cartridges.